(10) باب
Narrated Abu Dhar:
I said, "O Allah's Messenger (ﷺ)! Which mosque was first built on the surface of the earth?" He said, "Al- Masjid-ul-,Haram (in Mecca)." I said, "Which was built next?" He replied "The mosque of Al-Aqsa ( in Jerusalem) ." I said, "What was the period of construction between the two?" He said, "Forty years." He added, "Wherever (you may be, and) the prayer time becomes due, perform the prayer there, for the best thing is to do so (i.e. to offer the prayers in time).
Reference: Sahih al-Bukhari 3366
In-book reference: Book 60, Hadith 45
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 55, Hadith 585